Group 2: Wolves and Aspen in Yellowstone
· Explain the loss of Aspen trees and loss of willow groves in Yellowstone.
· How did scientists connect this loss to wolves in Yellowstone?
· How are ranchers coping with the reintroduction of wolves?
Read this article and answer the following question:
http://www.npr.org/templates/story/story.php?storyId=129666117
· In the Northern Rockies how many wolves have wildlife rangers and ranchers killed since the first 66 wolves were reintroduced into Yellowstone and central Idaho since the mid-1990’s?
· Does your team think wolf populations should be decreased inside Yellowstone National Park? Explain your position on this.

Our video segment was about wolves in Yellowstone National Park. In this video scientist talk about how the park has been losing wolves over the past few years. The wolves have been dying because of people hunting them. They started hunting them in the 1990's. Since then the trees have not been able to grow.The trees cant grow because the wolves have not killed herbivores and there over eating small new trees. Since the wolves have been killing the rancher's livestock they put tracking collars on the wolves. About 1,400 wolves have been killed by ranchers and wildlife rangers since introduced in the mid 1990's.

Here is more background on the connection between the Aspen and willow trees and the wolves in Yellowstone Park from the Strange Days Website. http://www.pbs.org/strangedays/episodes/predators/experts/yellowstonewolves.html
"When hydrologist Bob Beschta arrived in Yellowstone in 1996, he noticed something odd with the Lamar River. The stream was over-widened, the banks were eroding and precious soil was sloughing off down river. Vegetation that used to line and safeguard the riverbanks had vanished. What was going on?
Meanwhile biologists Bill Ripple and Eric Larsen were probing into another mystery – the disappearance of aspen trees in the park. At first they considered climate change. But if that were the cause, they reasoned, aspens should be declining throughout the area. Instead they found that aspens outside the park were flourishing. Next they turned to fire to see if possibly a reduction in the number of forest fires in the park was hurting the aspens. (These are trees that in fact thrive after a burn.) But the huge fire of 1988 ultimately produced few large trees.
Finally, Ripple and Larson decided to look within the aspens themselves. Drilling cores from nearly a hundred trees and counting growth rings, they determined that most the trees were at least 70 years old. It appeared that the aspen trees had stopped regenerating around the 1930s.
One significant change happened in Yellowstone back then. All the park's resident wolves were dead. Between 1883 and 1917 more than 100,000 wolves were killed for bounty in Montana and Wyoming alone. By the 1970s they were listed as endangered in the United States.
In an intensely controversial act performed for an entirely different set of reasons, biologist Doug Smith and his colleagues introduced 31 gray wolves from Canada to Yellowstone starting in 1995. What grabbed the headlines was the politics of predators. But the effect of these wolves on the Yellowstone ecosystem would become the more enduring story. Research suggests that the elimination of Yellowstone's wolves allowed the elk to browse aspens and willows brazenly. Though other factors may have played a role, it seems the disappearance of trees and streamside vegetation (and the accompanying loss of beaver and songbird habitats) can be traced to the missing wolves. It would appear that Yellowstone needs its top dog to keep elk on the run and its vital plant and animal diversity intact."


1) The loss of Aspen and Willow trees in Yellowstone National Park has been caused by herbivores. The herbivores have been over grassing on the small vegetation so new trees can not grow.

2) The loss of wolves meant that most herbivore had no major predator in the area. With the loss of death in herbivores the population flourished. After they flourished they were eating to much plant life.

3) The ranchers coped with the wolves by putting tracking collars on them so if the killed there livestock they would go out and hunt them.

4) 1,400 wolves have been killed by ranchers and wildlife rangers since introduced in the mid 1990's.

5) I think they should not kill them in the park if they are not doing anything. If there are trouble wolves than they should kill them. Wolves are apart of the Eco system and without them herbivores would run about with no natural predator.2008-08-01_Old_Denali_Highway_and_Denali_284.jpgWolve picture Where picture was found.

60/75 points